The above-referenced invention relates to vehicle heating, ventilation and air-conditioning systems, and more specifically to a device to partition hot and cold air for directing airflow to different portions of the vehicle interior.
Vehicle ventilation systems have long been utilized in vehicles to provide comfort to the vehicle occupants. Initial ventilation systems comprised a simple duct that was opened or closed by a manually operated valve directing outside ambient air to the vehicle interior. Through the years, consumers have desired increased interior comfort and manufacturers have delivered systems to satisfy consumer demand for improved interior temperature control. Advances made over the years include directing air through a heated core for delivering hot air to the vehicle interior and also for delivering hot air to the windshield to keep the windshield clear of frost and moisture. Subsequently, air conditioners have also become commonplace accessories in vehicles to provide cool air for the comfort of passengers in summer""s heat.
Heating, ventilation, and air-conditioning systems in today""s vehicles now provide total interior climate control. These new systems automatically maintain a desired temperature by delivering an appropriate mix of ambient, cooled, and heated air to the vehicle interior. More advanced systems also permit occupants to select a desired temperature for their individual zones and automatically maintain these zones at the pre-selected temperature. Such operation necessarily requires the automatic operation of the vehicle HVAC system wherein the ambient, cooled, and heated air are directed into an air distribution module to be ducted to the desired areas of the vehicle.
A prior art HVAC system is shown generally at 10 in FIG. 1. The vehicle HVAC system 10 is comprised of core module 12 and air distribution module 30. Ambient outside air or recirculated interior air is directed to air inlet 14 and is subsequently directed through air-conditioning evaporator 16 by the HVAC blower (not shown). After the air exits from evaporator 16 to pass between point 19 and wall 20, part of the air is directed through cool inlet area 22 and part of the air is directed to warm air passage 24. Inlet 22 and passage 24 are variable in area depending upon the position of air mix door 18. Air mix door 18 is hinged to pivot such that the position of air mix door 18 is directly related to the desired air temperature of air to be output to the interior of the vehicle. Thus, to obtain the maximum amount of cool air, air mix door 18 is rotated counterclockwise to maximize the area of cool air inlet 22. If heated air is desired, air mix door 18 is rotated clockwise to create a warm air passage 24 thereby diverting a portion of the air-flow exiting from evaporator 16 to flow through heater core 26 and duct the heated air through heated air inlet 28. An intermediate position of air mix door 18 facilitates a mixture of cool and hot air simultaneously entering air chamber 32 of air distribution module 30 to provide air at a desired temperature.
Air distribution module 30 typically has three designated outlets for delivering the conditioned air to different portions of the vehicle. These outlets are generally referred to as a defrost outlet 36 for delivering air to the interior surface of the windshield, vent outlet 40 for delivering air to the upper portion of the vehicle interior, and a heater outlet 44 for delivering air to the foot wells of the vehicle interior. Valves 34, 38, and 42 can be selectively positioned in closed, opened, or intermediate positions to place the desired HVAC system in the desired function. The HVAC system 10 is typically located in the center of the vehicle as are outlets 36, 40, and 44. Although there may be some mixing of the air upon entry to air distribution module 30, it is readily apparent that in such a configuration cool or ambient air is biased to the defrost outlet 36 and the heated air is biased to the heater opening 44, thereby causing a large temperature split between the defrost and heater airflows.
The defrost outlet 36 concentrates defroster airflow to the interior portion of the windshield to clear the windshield of frost or fog. Since the airflow from the heated air inlet 28 enters the distribution module at a lower point than the air from the cool air inlet 22, cool air is most proximate to defrost air outlet 36. Thus, the top defrost outlet 36 is prone to discharging air that is substantially cooler than the air discharged through heater outlet 44 when air mix door 18 is in an intermediate position. In some cases this temperature differential can be as much as 40 degrees Fahrenheit. When the vehicle windshield is fogged or frosted over, it is desirable to have heated air ducted out of defrost valve 36 instead of cool air. U-shaped channels have been utilized in the past in attempts to channel additional heated air from the heated air inlet 28 to defrost valve 36, however these channels have not produced the performance desired.
Thus, there is a need for an HVAC system for use in vehicle heating, ventilation, and air-conditioning systems that provides a more efficient distribution of heated air to the defrost valve for more rapid clearing of fog or frost from the windshield.
In one aspect, the present invention includes an air partitioning device for a vehicle heating, ventilation, and air-conditioning system to divide a hot air stream into separate portions. The air partitioning device comprises an L-shaped front portion including a base leg and a dividing leg, and also comprises a tail portion extending from a back of the front portion, the tail portion oriented angularly to the dividing leg.
In another aspect of the present invention, a vehicle heating, ventilation, and air-conditioning module is of the type having an air conditioning evaporator through which a cold air stream is delivered through a cold air outlet, and a heater core through which a hot air stream is delivered through a hot air outlet, such that the cold air outlet and the hot air outlet are oriented to cause the hot and cold air streams to mix after passing through their respective outlets for further distribution in a vehicle. The module further includes at least one air partitioning device comprising an L-shaped front portion having a base leg and a dividing leg, and a tail portion extending from a back of the front portion. The air partitioning device is affixed over the cold air outlet and positioned with respect to the hot air outlet to divide a portion of the hot air stream to bypass the cold air outlet.
Yet another aspect of the present invention is a method of dividing a hot air stream in a vehicle heating, ventilation, and air-conditioning module having a hot air stream exiting from a hot air outlet adjacent to a cold air outlet exiting a cold air stream for mixing the hot and cold air streams to prevent the divided portion of the hot air stream from mixing with the cold air stream. An air partitioning device is formed having an L-shaped front portion including a base leg and a dividing leg and further having a tail portion extending from a back of the front portion. The air partitioning device is affixed to the vehicle heating, ventilation, and air-conditioning module such that the base leg covers a portion of the cold air outlet and the dividing leg and tail portion separates the hot air stream into a portion that mixes with the cold air and an auxiliary hot air portion that bypasses the cold air opening.
These and other features and advantages of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.